A zipper locking device for luggage cases of U.S. Pat. No. 4,854,139 to Scelba comprises a loop (14) pivotally mounted on a housing for trapping and locking a pair of sliders of a zipper fastener on a luggage case, and the housing provided with a combination lock which may be unlocked for lifting the loop to free the sliders.
However, whenever locking the sliders of the zipper fastener on the luggage case, the two pull tabs (36A) and the two sliders (36) should be carefully and linearly arranged on the base portion (86) of the housing frame (44) in order to be trapped into chamber (88) of the loop (14) for locking the sliders of zipper. Once the luggage case is moved or vibrated inadvertently, the pull tabs may be pivotally slid away from the trap location of the loop (14), thereby causing an inconvenient locking operation of the zipper locking apparatus.